Black water in fresh water tank

[Persistent]

Black particles in fresh water system:

Black hose or pipe liner is deteriorating. Many hoses and flexible connecting lines are lined with black rubber.

Black rubber seals are deteriorating.

Iron particles from deep well come out black and turn rusty red (often accompanied by sulfur dioxide smell).

Carbon particles from a carbon water filter filter. You may have an old water filter somewhere that is now breaking down.

Organic stuff growing inside system is breaking down. (This is the only one that bleach will help with.)

I wish you good luck and happy trails ahead!

[lrgomez1976]

During your cleaning, you need to take the unit out for a spin and let the water and whatever else you are using splash around the inside then drain.

[propchef]

OP, have you considered having the water tested to know for sure?
https://www.epa.gov/sites/production...tertesting.pdf

Bleach (chlorine) as sanitizer in city water is somewhere around 50 ppm. Bleach used as a stand-alone sanitizer should be no more than 100 ppm. Anything more causes lingering odors and, as noted, is hard on the system. Test strips are cheap and widely available at WalMart, Home Depot, Amazon, etc. https://www.walmart.com/ip/VersaPro-...rips/170534951

[Keith55]

rough one but in a stick and bricks I had sulphur in the well. Used bleach and a carbon filter that took it out.

I am with the poster that said the black could be carbon particles. Could the old owner have had sulphur water and threw in a carbon filter?

I had the carbon filter on my sticks and bricks do that when I didn't install it correctly.

[Ray,IN]

When the fresh water tank is not completely filled with bleach/water solution the tank cannot be sanitized. It requires direct contact to kill bacteria and virus.


reference: https://www.rvbasics.com/techtips/sa...er-system.html

[LETMGROW]

Maybe the OP should back up and try to find the actual source of the black spots.
Using the same hose you are using to fill the tank with run some water into a clean pail and check for black particles. If the water is clear proceed from there.
Drain some water directly from the tank drain into a clean pail and check for black particles. If particles are present, the tank is likely the source. If the water from the tank comes out clean, disconnect the outlet hose from the water pump and with a hose connected to the outlet, pump some water into a clean pail. If there are particles present there is a problem within the pump such as a faulty impeller or check valve etc.
If city water is hooked up to the city water inlet does the water coming out of faucets or into the toilet(s) have particles in it after running a few minutes. There may be some residue left in the plumbing if it came from the tank or the pump. If the water clears up then the particles return after switching back to the tank the plumbing beyond the pump would appear to be alright.
This is no more than a process of elimination.

[Gary RVRoamer]

If you have a water filter inline, either built in or on the hose, that's a potential source of black flecks (carbon granules) and a badly decomposing filter will indeed turn the water blackish.


The smell is most likely from the heater tank, a microbe that thrives in hot water and excretes a sulfur compound. Sanitizing the entire system, heater tank included, is the way to get rid of it. However, it comes back if the source of the water has the microbes, e.g. a well or contaminated hose.


It's possible you took on water from a sulfur spring - they are common is some regions (central Florida, for one). That can cause odor and discoloration too. Plus it really gums up a water filter. A thorough flush usually gets that out of tank & lines, but toss the filter away. There is no saving that.

[Flyer 516NG]

My motorhome has a 90 gallon fresh water tank. I use 1 tablespoon of pool shock in my tank to sanitize it.

[US1]

I went to drain the 20 gals of water and bleach and low and behold the mix foamed when drained. Read just yesterday of the no splash bleach doing this. RV is stored at brothers place in country with well water. I did hook up and use the city water connection and bypassed the water tank and WH just to flush out the lines and faucets. No specks and no smell, and no black toilet water. Then I Filled the water tank a little ( 10-15 gals) only to try and flush out the foaming bleach before the foaming gets out of hand. Very little smell and specks. Didn’t do anything with WH. Waiting till I bring the RV home this weekend to do the thorough flush and sanitizing using our city water vs well water. Should note, there was one of those blue water filters in the stash of cleaners the PO left, so I know he’s used them. There is currently no filters in use.

[charliez]

Black water in a toilet can easily be the seals in the toilet breaking down. If it's only black there, then I would start with that.

[lrgomez1976]

I was thinking the same thing about the fresh water filter especially new filters. Hook it up to the fresh water hose and run the water prior to connecting to the house. You would be surprised on all the black stuff that comes from the charcoal stuff in the filter. The black tank mixing with the fresh water... in my thoughts, no way. Now it could mix with your grey water if there is a leak or accidentally have a black and grey water valve open at the same time. Touching on placing chlorine in fresh water. Fill at least 1/2 way with fresh water, run until you get the chlorine smell and drive your unit around for a few miles as this will do a slashing motion in your tanks. I have actual filled the black water tank about 1/2 way with water (after its been emptied) and put about 2 or 3 cups of automatic dish washer detergent and drive it around for a few miles. It's so nice to come back to lemon smelling toilet prior to a trip.

[Airboss68]

Don't forget to check the strainer on the inlet side of your water pump.

[Mudfrog]

Originally Posted by Gary RVRoamer

If you have a water filter inline, either built in or on the hose, that's a potential source of black flecks (carbon granules) and a badly decomposing filter will indeed turn the water blackish.


The smell is most likely from the heater tank, a microbe that thrives in hot water and excretes a sulfur compound. Sanitizing the entire system, heater tank included, is the way to get rid of it. However, it comes back if the source of the water has the microbes, e.g. a well or contaminated hose.


It's possible you took on water from a sulfur spring - they are common is some regions (central Florida, for one). That can cause odor and discoloration too. Plus it really gums up a water filter. A thorough flush usually gets that out of tank & lines, but toss the filter away. There is no saving that.

Our rig was only a few months old when we encountered sulfur smelling water at a campground. Had a bit of discoloration that went away fairly quickly but that smell was released every time we opened a faucet for a couple of years after. Guess it got into the pex and was slow to dissipate.

[VegasFoodGuy]

Originally Posted by Keith55

rough one but in a stick and bricks I had sulphur in the well. Used bleach and a carbon filter that took it out.

I am with the poster that said the black could be carbon particles. Could the old owner have had sulphur water and threw in a carbon filter?

I had the carbon filter on my sticks and bricks do that when I didn't install it correctly.

The sulphur smell can be mitigated by putting peroxide directly into the water heater. about a quart of peroxide directly into the relief valve hole, let set 24 hours.